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(No Model.) 4 Sheets-'Sheet 1.

J. D. SMITH GAS ENGINE.

WITNESSES: INVENTOR:

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PU'ERS, Phulo-Lnnugraphlr. Walhinglnru D. C.

4, Sheets-Sheet 2.

i (No Model.)

' J. D. SMITH.

- GAS ENGINE. 7 No. 418,821 Patented Jan. 7, 1890.

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(No Model.) 4 Sheets Sheet 3.

J. DQSMITH.

v GAS ENGINE; I No. 418,821; Patented Jan. 7, 1890.

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\ WITNESSES nfPz'rzns. Phuwunmmphu, Washington. D. c.

(No Model.) I

- J. D. SMITH;

' GAS ENGINE. v

. Patented Jan. 7, 1890.

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A UNiTnD ST TES PATENT OF IC JAMES DOWNEB SMITH, OF, PHILADELPHIA,PENNSYLVANIA, ASSIGNORQF ONE-HALF TO JOSEPH L. FERRELL, OF SAME PLACE.

GAS-ENGINE.

- SPECIFICATIQN forming part of Letters Patent No. 418,821, datedJanuary V, 1890.

l Application filed April 18, 1885. lserial No. 162,624:- (No model.) d

To all whom it may concern.-

,have invented certain new and useful Improvements in Gas-Engines.

The following is a specification of my said improvements, referencebeing had to the acc'ompanying drawings, wherein IO the complete engineas seen from the oppositesides. Fig. 3 is a top or plan view thereof,and. Fig. 4 an end view thereof. Fig. 5 is a central vertical sectionthrough the axis of the motor-cylinder and adjacent parts on an I 5enlarged scale. Fig. 6 is a horizontal section through theignition-chamber and the valve by which it communicates with themotorcylinder. Fig. 7 is a vertical section on the irregular line to wof Fig. 5. Fig. 8 is an exterior end View of the motor-cylinder. Figs. 9

and 10 are sectional views (on a much enlarged scale) of theignition-valve at different points. Fig. 11 is a vertical sectionthrough the center of the passages by which air and gas are admitted tothe motor-cylinder, the scale 'ofthis and the succeeding figures beingstill further enlarged. Figs. 12, 13, and 14 are horizontal sections onthe lines 2 z, y y, or m, respectively, of Fig. 11.j..'Fig. 1.5 is aview,

partly in section, of the valve which is controlled by the governor ofthe engine. My improvementsare especially adapted for use in connectionwith that class of gasengines in which the charge is compressed be- 3 5fore ignition, although some of them are applicable to engines ofdifferent types.

Their nature and objects can be best explained in describing theconstruction and operation of the several parts.

Referring to the general exterior view of the engine, A represents thebed supporting the motor-cylinder B, which is surrounded with the usualwater-jacket, the water-circulation being maintained by means of pipe Ois the connecting-rod of the motor-piston; D, the iiy-wheel; E, the rodfor operating the valve mechanism, which rod is actuated by an eccentricmounted upon the'main 5o'driving-sl1a'ft in the usual manner.

The charge is supplied to the motor-cylinder by a pump, whosecylinder-is shown at J, and which is worked by means of a connecting-rodX, attached to a wrist-pin radially adjustable in a disk D, mounted uponthe driving-shaft.

K is a governor which controls in a mani nerto be hereinafter explainedthe ext'ent of Figures 1 and 2 areviews in elevation of v the chargeintroduced into the motor-cylinder.

N is a strong receptacle, into which under certain conditions thesurplus charge is forced by the action of the pump, and which for thatpurpose connects with the pump-cylinder J by a pipe P.

The igniting system is contained in an end extension B of themotor-cylinder B, by which the charge is conveyed from the pump-cylinderJ to the motor-cylinder B and ignitingchamber.

Y, Figs. 2 and 4, indicates the main inletpipe, which is connected withthe gas-supply, and G is the discharge-pipe leading from a large chamberF, into which the direct exhaust from the motor-cylinder takes place. i

The general operation of the apparatus is as follows: A charge ofmingled air and gas is pumped intothe motor-cylinder ata time when themotor-piston is at or near the outer end of its stroke. WVh en thepiston has been brought to its innermost position, said charge isignited, driving the piston forward and actuating the driving-shaft.This movement opens the exhaust-valves and permits the discharge of theproducts of combustion into the exhaust-chamberF, and thence into theopen air. In the meanwhile the return-stroke of the engine actuates thepumping mechanism, so that a fresh charge'is delivered into the cylinderand the operation is repeated.

Having thus given a most general descrip- 0 tion of the operation of themachine, I will now proceed to a detailed description of those portionswherein the present improvements consist. Thev motor-cylinder andadjacent parts are shown in vertical section in Fig. 5. 9 5 The interiorshell R of the cylinder surrounded by the water-jacket terminates in aconical compression-chamber 0%, into which the inlet-passage n for thecharge of air and gas leads.

As will be seen in the drawings, I00

this inlet directs the current of entering gas and air upward, so as toimpinge upon the upper surface of the shell R, the passage beingpreferably inclined, as shown. Beneath the inlet n is adownwardly-depending chamber L, partly surrounded by a water-jacket andcommunicating at 0 with the interior of the motor-cylinder. At thebottom of this chamber L is the exhaust-valve t, the actuat ingmechanism of which will be seen on referrin g to Fig. 1, but which willbe hereinafter described in connection with the description of the othervalve movements. W'hen open, the exhaust-valve conununicates with thelarge exhaust-chamberF, whose construction and functions will alsohereinafter be described.

The operation of the parts now under consideration is as follows: Thecharge of gas and airis introduced into the cylinderthrough the orificen and fills both the cylinder proper and the chamber L. The piston 7tbeing brought to its extreme innermost position, the charge iscompressed into the chamber m,and is then ignited in a manner which willbe hereinafter described. The ignition commences at the point I inFig.5, and primarily takes place in the conical chamber m of thecylinder proper. By reason, however, of the extended chamber L thecombustion of the whole charge is not instantaneous, but takesplacefirst in the compression-chamber m and subsequently throughout thechamber L. This method of protractiug the combustion has the advantageof relieving thepiston from a too sudden shock and is found to economizethe actual force of the charge in the best manner. Assuming thatcombustion has taken place (the inlet valve 19 being of course closed)and that the piston it has been driven to its extreme outward position,the exhaustvalve t is opened and the products of com: bustion rush outinto the exhaust-chamber F. The piston 7t" then commences itsreturnstroke and the exhaust-valve t remains open for a minute fractionof said return-stroke. it the same time the inlet-valve p isopened, and,owing to the direction given to the entering current at n, it flows intothe cylinder above the products of combustion, which are still passingout through the orifice 0. The cylinder proper is first filled, andfinally the chamber L. Thus the admission of the new charge, followingthe exit of the products of combustion closely, aids'in expelling morecompletely the residuum of the previous charge. The features ofimprovemcntin this connection are, therefore, the inlet-passage with anupward projection in the cylinder, the subjacent discharge passage, andthe chamber L, which forms both a supplemental combustion-chamber and aportion of the discharge-passage.

The next group of features to which my invention relates, and which mayproperly be described at this point, are the exhaust devices. I providea horizontal pipe G, leading from the exhaust-valve 6 into a large ex-.

haust-chamber F. This chamber F has a pipe G, which communicates withthe open air. The outer end of said pipe is provided with a case H, inwhich is seated a puppetvalve 71, opening outward. This valve h isintended to permit the discharge from the exhaust-chamber and to closeit against admission of the outside air. The interior of theexhaust-chamber, as well as a portion of the pipe G, is provided with awater-spraying device I, by which water is constantly injected upon theissuing products of combustion, the surplus water being discharged atthe bottom through the drip-pipe Z. I have found that this method ofconstructing the exhaust-connection reduces the volume to be expelled,and by producing a partial vacuum within the chamber F gives a softerexhaust. It also prevents theignition of accumulations of unburnedmixture, which sometimes occur in the exhaust-passages, owing to missedignitions in the cylinder or to defective adjustments of the valves. Thefeatures of improvement therein are the combination, with theexhaust-valve, of an enlarged exhaustchamberand discharge-pipe leadingfrom said chamber to theair; also the valve controlling the orifice ofsaid exhaust-pipe against backfiow of air and the arrangement of aspraying device within said exhaust chamber,

The next group of devices to be considered comprises the ignitingdevices" and parts adjacent thereto; In Fig. 6 is shown a horizontalsection through this portion of the apparatus. It will be seen that thechamber mot the motor-cylinder connects at its extreme end by means of ahorizontal passage 1 with a small chamber a situated within theextension B of the motor-cylinder. Communication betweenthis chamber 11,(which I term the ignition-chamber) and the compres sion-chamber m iscontrolled by means of the valve V. This valve is in the form of aspindle, preferably tapering, having a transverse opening or port 2,arranged to register with the-passage 1, and which I term theignitingport. Vhen the valve-spindle V is in the position shown in Fig.6, communication between the ignition-chamber 'u, and thecompression-chamber m is out off. \Vhen, however, the valve-spindle V isturned at right angles to the position there shown, the two chambers uand m communicate through the igniting-port 2. The valve movementispreferably such as to rotate the valve-spindle always in the samedirection,and thus for each complete rotation of said spindle the portis opened twice. The movementof the spindle may, however, be oscillatoryupon its axis instead of rotatory.

In addition to the ignition-port 2, the valvespindle has a supplementalport 5 (see Fig. 10) for the following purpose: Referring to Fig. 6, itwill be seen that a very small passage-way 3 extends from the rearportion of the chamber m to the spindle V and continues on jam otherside of said spindle until it; reaches the igniti'on-chamber u, itsorifice at this point'be'in'g covered by a perforated plate? 22. (Shownmore clearlyin Fig. 11.) The func-I tion of this passage-way 3 is topermit a small ;qu antity of mixture to pass through for the; purpose ofblowing the ignition-chamber clear of the products of, combustion leftfrom the? preceding charge.

opening of the igniting-port 2, and it is also It is necessary thatthis; should be accomplished in advance of the necessary that theadmission of the'mixture'g through said ports should be so conducted;

The arrangement In order to clear the i nition-chamber at the propertime with relation to the opening of the igniting-port 2, I- constructthe supplemental'port (see Fig. 10) in: the following manwhere it willthere be seen that as the spindle nerz Said Fig. 10 represents atransverse section of the spindle V on a; line through the adjacentpassage 3. It will be seen that a 7 small transverse passage is formedthrough the spindle V at 5, and'thata portion of the periphery of thespindle adjacent to each end of said passage5 is cut away, shown at 4.

The opening thusformed'constitutes the supplemen't'al port, and itsrelation to the main port 2 is shown in 'Fig'. Q'bythe dotted lines,

V rotates the supplemental port is opened a short ti-mein advance of themain port 2.

Thus in Fig. 9 the main port 2" is about to be opened; but for a shorttime prior to this the passages 4 and 5 of the supplemental port haveestablished communication through the passage 3. During the time thatthe port 5 has thus been opened a small stream of gas and air has beendischarged i'nto'the ignitionvchamber 'u, through 'thejoerforated plate22,

driving before it the products of combustion from the previous chargeofthe ignition-chamher in the following manner; At the end of theignition-chamber u farthest from the inlet 22, I provide" a smallpassage-way 6. In the enlarged port-ion 25 ofthe Valve-spindle V arearranged two ducts 31, leading to a diametrical passage q. "(Indicatedby dot- At each half-rotation of said spindle these ducts communicatewith ted lines in Fig- 6.)

an outlet-passage '6, leading from the end of the ignition-chamber'fu,and thus immediately after the ignitionof the gases has taken place andthemain' port 2 has closed -the rotation of the valve-spindle V opens anexhaust at that end of the ignition-chamberwhich is fartliest from theinlet 22. An opening 35' is formed inthe casing of the'enlarged portion25 opposite to the points at which the passage q comes to rest on eachhalf-rotation. The result of this arrangementi's, that the enteringgases at 22 drive before them the products of combustion of the oldcharge.-

stant-state of incandescence. When the'ig-' nition-chamber u issufficiently charged with the combustible mixture,ignition takes place,and the flame communic'atesthrough the portn and the passage-way 1 intothe cylinder,

Where it ignites the main charge, as has been before described. Besidesaffording a pro tection against the backing of flame, asbefore stated,the perforated plate 22 breaks up the entering current and obviates therisk of v cooling down the incandescent loop, which might take place ifthe current were directed upon it with full force.

In Figs. 6 and8 a sight-glass is shown in the cap 29, that covers'theignition-chamber. A hole 30 is piercedthrough the cap and the outer endof the hole is enlarged. -The bottomof this enlarged portion forms aseat for a glass disk 28, the remainingportion of the enlargement beingthreaded to receive a hollow cylinder, also threaded on its'exterior, bywhich the glass disk is secured in place. The object of this sight-glassis to provide means of viewing the flame as ignition takes place, sincethe color of the flame affords'the best indication'of correctproportions of air and gas mixture for perfect combustion. The featuresof improvement most prominent inthis group of devices are as follows:the construction of the Valve which controls the ignition-port in theform of a rotating spindle. Great difficulty has been heretoforeexperienced in operating the slide-valves ordinarily used for thispurpose, since they are exposed to the full shock of the. explosion andrapidly deteriorate. I have found that ICC the u'seof a rotating spindleexposes a mini- I mum of valve-surface to the action of the flame,andthat such Wear as does take place from said exposure is regular andself-compensating. By combining in the same spindle with theigniting-port proper the secondary port for allowing what may be termedthe leakage of the charge into the ignitionchamber and the exhaust-porttherefrom I drive out the products of combustion in the I preciserelation which is necessary to the opening of the igniting-port, and,furthermore, I obtain all of these three valve movements by a simplerotary movement of the spindle. The angular relation of thesevariousports in the Valve-spindle V is'indicated inthe drawings, and can be ofcourse varied to suit the conditions desired upon any particular enginewithout changing the principle of operation.

.The next group of (levices'compriies the valve movements of thisportion of the apparatus.

Referring to Fig. 1, it will there be seen that the eccentric-rod Eoscillates a toothed sector U, the teeth of which engage with a gear 6,mounted upon the projecting stem f of the spindle V. This gear isprovided with a pawl, which engages with a double ratchet-tooth securedto the projecting end of the stem f. Thus as the sector U oscillates itmoves the gear 6 and its pawl alternately in opposite directions, and ateach complete reciprocation turns the stem f (by means of theratchet-tooth) a half-rotation. Upon the sector U is pivoted atripping-pawl a. At each descent of this pawl a it strikes a lever-armTand raises the link S by means of said lever T. This link S isconnectedv with a horizontal link R, which is pivoted to therigidbracket Q, As the pawl 00 in its descent trips the lever T, the link Sraises the end of the horizontal link R and falls again after thepassage of the pawl abeyond the lever T. On the return movement of thesector the pawl turns upon its pivot, so as to pass the lever-arm T, andthen drops again, by reason of its weighted rear end, into the positionshown in Fig. 1. The downwardly-projecting stem at of the exhaust-valvet rests upon the horizontal link R, and each time that said link R israised the exhaust-valvet is opened and kept open until the pawl apasses the leverT. The lower end of this stem (1 is weighted, as shown,and is provided with a pawl b, which engages with a circularor crownratchet c, rigidly attached to the bottom of the chamber L, throughwhich the stem d of the exhaust-valve projects. It will be seen thateach time that the link R raises the valvestem d the pressure of thepawl 12 against the ratchet 0 will tend to rotate said stem, and on thedescent of the stem the pawl will slip past some of the ratchet-teethand take a fresh hold I have found that this constant rotation of thevalve-stem and valve prevents uneven wear of the valve upon its seat andthus prolongs its efiiciency. Any suitable rotating device will ofcourse accomplish the desired results.

The next group of devices are those which relate to the operation of theair-pump and V the admission of the charge into the cylinder.

The interior construction of the air-pump is of any ordinary character,and its piston is operated, as before stated, by the rod X. By referringto Fig. 2 it will be seen that the wrist-pin S, carrying the piston-rodof the air-pump, is placed in a radial slot in the disk D to permitadjustment of the stroke of the air-pump piston. It sometimes happensthat an engine has 'but small duty to perform for weeks or months, andif the stroke of the pump is shortened to suit the requirements in suchcases it will result in a lighter-running engine and a saving of gas. Iam aware that this is a common device for many classes of machinery anda variety of pumps in general use; but I believe no gas-engine has everbeen provided with a means of adjusting the charge constantly deliveredby its pump/the usual method being to allow one or more reciprocationsof the motor-piston without fresh charges. This last-mentioned system ofregulation should only be applied to temporary or momentary charges ofburden, as described farther on.

In Fig. 11, J is the end of the pump-cylinder, and 17 is the opening bywhich it draws in and expels its charge. This charge is composed ofmingled gas and air, the gas coming through the supply-pipe Y and theair coming in at the opening 20. (Shown at the bottom of Fig. 11.) I VThe valve system which controls the entrance of the two components willnow be described. The opening 20 is at thebottom of a vertical chamber11, which is perfectly cylindrical in form. The upper end of thischamber communicates with a horizontal passage-way 8, theopening'between them being so formed as to constitute a valve-seat forthe valve 9. This valve 9 is hollow or tubular, as shown,and has at itsupper end a vertical guiding-stem 10, by which its upward movement islimited, the limitation being regulated by a set-screw 19, arrangedabove the end of the stem 10. I prefer to construct the stem 10 in aseparate piece from the valve 9, and let it seat itself in the centralopening of the valve 9; but I also provide notches in that portion ofthe stem which is in contact with the valve 9, so that a freepassage-way is left from the tubular interior. Each time that the pumpdraws in a charge the valve 9 is raised and air flows in by the passage20 into the passage 8. I accomplish the admission of gas at the sametime, but without direct communication with the air-inlet, in thefollowing manner: \Vithin the cylinder 11, I mount so as to leave anannular space between them a second hollow cylinder 12. The gas-inletpipe Y communicates with the interior of said cylinder 12, near whosebottom is a peripheral seat 13. Upon the valve-seat 13 the lower end orstem 15 of the valve 9 rests, so that when said valve 9 is in its lowestposition the opening 13 is closed. The hollow stem 15 of the "alve 9 hasnear its lower end a series of radial or lateral openings, which areshown clearly in the sectional view of Fig. 13. A bushing 26 is arrangedwithin the cylinder 12 for the stem 15 to slide in, and the bushing hasin its lower portion an open annular space 16, surrounding the stem 15.About the middle of this annular space 16 is arranged a collar 14,having a series of vertical openings through it, as shown in Figs. 13and 14. This collar is of such vertical height and so arranged that whenthe valve 9, and consequently the stem 15, are in their lowest positionthe collar 14 is opposite to and covers the whole orthe greater portionof each lateral opening in the stem 15; but when the valve 9 and stem 15are raised said openings in the stem come opposite to the annular space16 above the collar 1-4. Thus communication is established from the pipeY, (when the stem '15 israised from the seat 13,) through theperforations of the collar'14, into the annular'space' 16 abovc thecollar, thence through vare opened and closed by the movement of asingle piece, and therefore in uniformity both as to time and relativeextent of opening. Where the valves are separate or not coupled, it isfound that they sometimes act irregularly, especially when the fullcharge is not being pumped. This is entirely avoided by my arrangement.The moment that the pump commences its back-stroke all these valvesclose instantly, and communication both with the gas and air supply iscutoff.

To insure a thorough commingling of the air and gas, I applyacrossthe'opening which leads from the passage. 8 to the inlet 17 of theair-pump a quantity of wire-gauze 18. The passage of the currents of airand gas through the meshes of the wire-gauze breaks up the stream'andcauses an intimate mixture, and the operation is of course repeated uponthe return-stroke of the pump, which forces the mixture into themotor-cylinder; Supposing the pump to have drawn in its charge of airand gas through the combined valve system whichhas just-been described,the return-stroke of the pump closes said system of valves and forcesthe mixture of air and gas along the-passageway 8 to the valve 1), whichcontrols the opening n, into the motor-cylinder. This valve is lifted bythe pressure beneath it and falls as soon as the pump. has completed itsstroke, thus cutting off the egress of the mixture from themotor-cylinder. Said valve 19 is provided with a pawl-and-ratchet device'5 1", attached to its stem 19 and case, respectively,-and similar tothat previously described in connection with the exhaust-valve 2f, theobject being, as before stated, to cause the continuous slow rotation ofthe valve.

The most prominent feature of improvement inthe group of devices justdescribed is the peculiar construction of the double valve by which gasand air are admitted through the same general inlet, but without comingin contact until actually within the main passage-way of the machine.

The next feature of improvement relates to the governing devices.Beneath the pumpcylinder J I arrange-a second cylinder or receptacle N,of about the same cubic capacity as the pump-cylinder, and establishcommunication between the pump-cylinder Jand said cylinder N (which Iterm the overflow-cylinder) by means of a pipe P. In this pipe P, whichis shown in the detail view of Fig 15, is a balanced valve 21, turned bymeans of the connecting-rod g, which is attached to the lever 77.,operated by the governor K;

.WVhen the balls of the governor move outward,

the lever h pulls the connecting-rod g, so as to open the 'valve 21.When, on the other hand, the balls move inward, the lever it pushes the.connecting rod g and closes the valve. Supposing the pump at this timeto be in operation, if the speed of the apparatus is too great, theaction of the governor K upon the valve 21 permits the discharge of thewhole f or a portion of the pumps contents into the overflow-cylinder N,since the mixture from the pump finds a more ready exit through the pipeP than it does through the inlet p of the motor-cylinder. Themotor-cylinder is thus left without any new charge of air and gas,

and no ignition takes place therein, so that the-momentum of thefly-wheel alone continues the action of the engine. Should the omissionof a single chargein the motor-cylinder thus brought aboutbeinsufficient, wever, to reduce the speed of the engine, the balls ofthe governor still remain in their outward position and the valve2l inthe pipe P still remains open, so that on the return-stroke of the pumpno new charge of air'and gas is drawn in through the main inlet ofvalves therefor; but the contents of the overflow-cylinder are merelydrawn back again, and so long as the condition of too great speed existsin the engine the pump would merely continue to draw its charge from andredeliver it into the overflow cylinder. In practice, however, theoperation cannot continue, since the speed of the engine is immediatelyreduced by the failure to supply fresh charges to the motor-cylinder, sothat the action of the governing devices soon closes the valve so far asis necessary to maintain a uniform speed, and the normal action of thepump is resumed,

supplying a fresh charge at each reciprocaor accidental variations ofburden upon-the engine, while the more permanent adj ustment of thecharges is preferably effected by means of theradially-adjustable"wrist-pin t in the disk D, as before stated.

' I claim 1. In combination with the compressionchamber of a gas-enginecylinder, an inletduct leading thereto near its rear end and an outletarranged upon the same side of the chamber and between the inlet and thepiston, the line of projection of the inletrduct being suchas to strikethe opposite side of the chamber or cylinder, whereby when the charge isadmitted before the completion of the exhaust the identity of theentering and outgoing currents is maintained, substantially in themanner set forth.

. whereby as said spindle moves the said supplemental ports are openedin advance of the opening of the main port, substantially as set forth.

4. The combination, with the supplemental inlet-port leading into theignition-chamber, of the perforated plate arranged over the opening ofsaid inlet-port, whereby backing of flame is prex'ented and the enteringourrent is broken up to avoid direct impingement upon the ignitingdevice.

5. The combined gas and air inlet consisting of a hollow valve theexterior periphery of whose head rests upon a seat formed in theair-channel and the bottom of whose stem rests upon a seat in thegas-channel, said stem being provided with lateral openings, and whichlead into a chamber of the gaschannel above said last-mentioned seat,and said chamber being provided with a perforated ring fitting closelyaround the valvestem and of such vertical height as to control thelateral openings of the stem, the whole combined and operatingsubstantially as set forth.

' JAS. DOXVNER SMITH.

Witnesses:

'IHos. M. SMITH, GEO. A. VAILLANT.

